Cooperation and group living is widespread among animals and at first glance manhandles the traditional theory of natural selection proposed by Darwin 200 years ago. Animals are predicted to compete among each other and not to cooperate. Explaining cooperation and the maintenance of societies in nature has been one of the major tasks for behavioural ecologists in the last few decades and there are still a lot of unresolved issues. I am interested in cooperation in a broad sense with a particular interest in how animals manage their relationships within a group. Exactly as fishes evolved gills to survive under water, social animal evolved specific strategies or capabilities in order to resolve the problems they face in their all-day life within their community. I am investigating some of the costs and benefits emerging from sociality as well as the different strategies that are employed to reduce the costs, notably those induced by conflicts, by studying colonies of wild living rooks (Corvus frugilegus) around Neuchâtel. This highly social corvid species lives in large colonies during the breeding period and forms flocks throughout the year. Hence, rooks are a particularly well suited species to study conflicts and cooperation in the wild. Furthermore, most recent studies that were interested in the sociality of this species were conducted in captivity and hence, evidence coming from the field is still needed and it is one of the aims of the current project to fill this gap.

Cooperative personality

During my master thesis work I realised relatively soon that the individuals I observed differed from each other in their behaviour. For instance, some individuals were more reactive toward intruders than others or some males shared more food with theirfemales than "average males", i.e., were more generous. Animal personalities have been defined as consistent behavioural differences between individuals and have been documented in a wide range of species. Astonishingly, the cooperative - uncooperative tendency of individuals, i.e., cooperative personality type, is still a relatively unexplored topic. Hence, I aim investigating whether rooks differ in their tendency to cooperate, whether these differences remain constant across different contexts throughout the year and what implication these differences have for individuals living in a group.